An aortic stent-graft may include a tubular graft extending from a proximal end to a distal end, the graft comprising a proximal sealing portion and an intermediate portion, wherein a proximal end of the intermediate portion abuts the distal end of the proximal sealing portion. At least one sealing stent may be attached to the proximal sealing portion. A first fenestration window is disposed in the intermediate portion. The first fenestration window has a length determined by the equation L=1.23*D−24 millimeters, where L is the length of the first fenestration window. D is between about 24 millimeters and 45 millimeters.